This invention relates in general to a device for terminating an electromagnetic shield on a wire. In particular, this invention relates to an improved structure for such a device that terminates an electromagnetic shield between terminal ends of shielded single and multi-core wire assemblies, and at a point where a shielded portion of the wire assembly transitions to a non-shielded portion of the wire assembly.
With the proliferation in use of electronics and electronic equipment, it has become increasingly important to protect sensitive electronic equipment from the negative effects of electromagnetic interference (EMI). One way to protect electronic equipment is to provide an electromagnetic shield over wires that are connected to the equipment.
The electromagnetic shield attenuates magnetic fields generated by the current in the wires, reducing the potential interference with nearby electric components. This may be particularly important in an environment in which there are many electric components located relatively close to each other and where electromagnetic compatibility (EMC) is important. The electromagnetic shield offers flexibility in packaging high voltage electronics in an electrical system, such as in a vehicle, and reduces susceptibility to the electromagnetic fields emitted by the shielded wire of sensitive electronic components that are in close proximity to the shielded wire.
A conventional electromagnetic shield may be constructed from several small gauge wires braided over the internal signal and/or power wires for which shielding is desired, or may be an outer layer of metal that is coaxially arranged with a conductive wire. The electromagnetic shield absorbs radiated energy and distributes the energy away from the internal conductors and their connected electronic component. The wires or metal layer forming the shield are typically terminated and grounded, such as at one or more connector interfaces in the electrical system.
One common method of terminating and grounding such electromagnetic shields is a backshell assembly with a compression ring, but such backshell assemblies are difficult and time-consuming to assemble and disassemble. Conventional backshell assemblies are typically embodied as connectors attached to a terminal end of one or more electromagnetically shielded wires and which allow the one or more electromagnetically shielded wires to be grounded and connected to another electronic device. In such conventional electromagnetic termination connectors, environmental protection, i.e., sealing to prevent corrosion and contamination, is provided by the connector. Also, conventional electromagnetic termination connectors do not allow for interruption or termination of electrical wiring systems between devices in locations where an electromagnetic shield is not necessary, i.e., where EMI is not present, and therefore where EMC is not required.
It would therefore be desirable to provide an improved structure for a device that terminates an electromagnetic shield on shielded single and multi-core wire assemblies without need for a connector.